Trying to figure out what to feed my chickens

Do kids like candy? Same with chickens and Scratch grains--not a complete diet and not healthy for long term egg production and long life.
It is not the "processing" the your pullets do not like. They like eating "candy" better!!! Did they like Starter crumbles? Then feed it until they are laying. It is a complete feed but more protein than desired for layers. Scratch is "dessert", and very little before bedtime means going to roost with a full crop, they will process it overnight, ready to go in the morning. I whistle to my birds before the Scratch and they come running, whenever I whistle them in!

I, too, am a farmer, and save Spring Wheat and a little Barley to mix with their commercial Scratch feed. (and to offer Pheasants when ice and snow make their hunt for food more difficult.--along with Grit.)

Oyster Shell should not be fed until the birds are laying. Start/Grow feeds have the calcium, etc, that makes strong bones and prepares their systems for eggs production--when mature! You may have first egglaying more difficult if they have been eating more Oyster Shell than desired--or hopefully, they will be ignoring it for most of the time? Then, after laying begins, offered free choice, will keep the eggs shells strong. Egg shells are certainly okay, too. And offer Grit, to keep the gizzard doing its job, to make all their food ground finely, and able to be absorbed in the intestines.

Layer crumbles are a complete feed, but you might try Layer pellets when they are laying well, and see if it is more appealing and less wasteful. I raise Bantams and mine are too small to eat pellets readily.

And all commercial feeds are not alike in mix and texture. If you can try different brands as time goes by, you may find one that is better accepted by your birds. I am afraid that to cut costs, now, we find sometimes find 40# bags instead of 50s in some brands, and some additives are omitted. Keep as little feed on hand as you are able, (I get to town seldom, so must have at least 30 days supply on hand), as Vitamins A & D are lost with storage. And then the additives that are now also offered separately will be necessary, especially for those who hatch eggs.

Feed companies would not stay in business if they did not do the research and always keep abreast of results of use of their feeds by the largest producers of eggs, meat. Since most all of us who keep chickens for our own eggs keep our birds longer than the huge egg producers, the additives (NOT found in grains) are what keeps our birds laying for years--my 11 and 12 year old hens have only stopped laying this summer--fewer eggs to be sure--but still look like pullets. Cod liver oil sandwiches, hand fed, have been their main additives and they have produced strong healthy chicks over the years!

However, different parts of the country, different climates, different housing or pasturing--and different experiences will make our choices different also. Yours may work well for you....

Great Grandparents who free ranged, feed little besides their own grain or "scraps" were not concerned about nutrition--collected the eggs, and had "Chicken every Sunday" by culling the roosters and less thrifty of the hens as the year went by--letting hens hatch what they could and so the generations went on!

Chickens remain one of the best projects for any who like them--in the country and often in cities (certainly in European cities, keeping chickens is common and even there, they must be protected from the Fox!) Good luck.....